// File: FileIO4.java
//
// Author: Rahul Simha
// Created: August 18, 1998.
//
// A useful function to extract information from
// property files.

import java.util.*;

public class FileIO4 {

    // Parameters:
    //   inString: the property string (e.g. "radius=0.9")
    //   property:  the property name (e.g., "radius")
    // The value is assumed to be a real number.

    public static double readProperty (String inString, String property)
    {
	// Obtain a copy of the StringTokenizer object.
	StringTokenizer st = new StringTokenizer (inString);
	
	// Get the first token, specifying the delimiter.
	String firstPart = st.nextToken ("=");
	
	// Trim whitespace on either side - a String function.
	firstPart = firstPart.trim ();
	
	System.out.println ("First part: " + firstPart);
	
	if (!firstPart.equals (property)){
	    System.out.println ("Improper string: " + inString);
	    System.exit (0);
	}
	
	// Get the next token, now allowing for end-of-line.
	String secondPart = st.nextToken (" =\t\n\r");
	
	// Trim whitespace.
	secondPart = secondPart.trim();
	
	System.out.println ("Second part: " + secondPart);
	
	// Read the number in the second part using the library's
	// Double object.
	try {
	    double d = Double.parseDouble (secondPart);
	    return d;
	}
	catch (NumberFormatException e) {
	    System.out.println ("Second part not a number: " + secondPart);
	    System.exit (0);
	}
	return 0;
    }

    public static void main (String[] argv)
    {
	// Test
	double d = readProperty ("x=5", "x");
	System.out.println (d);
	
	d = readProperty ("center.x=5", "center.x");
	System.out.println (d);
	
	d = readProperty ("center.x=5   ", "center.x");
	System.out.println (d);
	
	d = readProperty (" center.x = 5   ", "center.x");
	System.out.println (d);
	
    }

}